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Andrews WW, Goldenberg RL; National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.Andrews WW, et al.Semin Perinatol. 2003 Jun;27(3):231-8. doi: 10.1016/s0146-0005(03)00006-5.Semin Perinatol. 2003.PMID: 12889590Review.